Severity of vWF Degradation Depends on LVAD types: Preliminary Results from a Multicenter Prospective Study

Objectives: Left ventricular assist device (LVAD), as either bridge to transplant or destination therapy, has been used for patients with end-stage heart failure. However, supraphysiologic shear stress derived from continuous-flow LVADs causes von Willebrand’s factor (vWF) large multimer degradation and subsequently resulting in bleeding during follow-up. This study was aimed to compare the impact of various continuous flow pumps on vWF large multimer.

Methods: A multicenter prospective observational study was conducted among the patients who underwent LVADs implantation between July 1, 2017 and September 21, 2018 at eight institutions. Blood serum were taken preoperatively, 1 week, 1, 3, 6, and 12 months postoperatively. The index of vWF large multimer was measured according to the same density of vWF antigen and then calculated.

Results: A total of 49 patients underwent LVADs surgery during the study period, among them, 38 HeartMate II, 6 Jarvik2000 and 5 EVAHEART II were implanted. Preoperatively, there was no significant difference in terms of vWF large multimer index among three groups. However, vWF large multimer index decreased significantly 1 week after HeartMate-II and Jarvik2000 implantation (p < 0.01), continued to be low at 1 and 3 months in Jarvik2000 group, and 1, 3, and 6 months in HeartMate-II group. In contrast, the patients in EVAHEART II group exhibited no statistically significant changes in vWF large multimer index from postoperative values.

Conclusion: Our data indicated that centrifugal LVADs EVAHEART II could preserve the vWF large multimer, whereas persistent postoperative loss of vWF large multimers was present in HeartMate II and Jarvik2000. However, further study on vWF activity, clinical outcomes, such as bleeding event and mechanisms for such differences derived from pump types should be undertaken.